A Solution to the 4015 Problem on W2K3 Server *if* You Did Something Silly
by Zube (zube@stat.colostate.edu)
Created: Aug 13, 2006
Updated: Aug 13, 2006
http://www.stat.colostate.edu/~zube/docs/4015.txt

[Additions, suggestions, corrections or thoughtful discussion always welcome.]

I rebooted a Windows 2003 SP1 server and got the following 4015 error in 
the logs:

Error:  DNS server has encountered a critical error from the Active
Directory.  Check that the Active Directory is functioning properly.
The extended error debug information (which may be empty) is "".
The event data contains the error.

0000:  51 00 00 00     Q...

Most of the answers I found via searching dealt with complex configurations.
The fact that I had never seen this problem before made me suspicious that
is was just something that I did, but I didn't know what.  

Stupidly plowing ahead, I tried setting this reg key:

Added to HKLM\System\CCS\Services\NTDS\Paramaters\Repl Perform Initial Synchronizations 

DWORD 0

and rebooted.  This was supposed to help if you have DNS integrated into
AD, but it got worse.  I started getting these too:

Error:  4004.  The DNS Server was unable to complete directory
service enumeration of zone ..  This DNS server is configured to use
information obtained from AD for this zone and is unable to load the
zone without it.  Check that the AD is functioning properly and repeat
enumeration of the zone. ....

0000:  2a 23 00 00   *#..

Ok, so I removed the key and rebooted.  Same original problem.  

So I checked the DNS entries against another Windows 2003 SP1 server.  That
server had X DNS entries and X-8 reverse (in.addr-arpa) entries.

But the one with the problem had X DNS entries and X-9 reverse entries.
Since I configured the two similarly, it was clear that one forward
entry was missing.

And of course, it was for the server itself.  Once I added the missing 
(forward) PTR record for the server itself in the DNS, everything started
working again.  I was also clued to this because running nslookup on clients
and the server itself claimed that it couldn't find the server, but if
I set nslookup to query the IP of the server, resolution worked.

My simple guess as to what happened:  while modifying DNS entries, I 
mistakenly deleted the PTR record of the server which caused this big mess
and the best W2K3 could do was give me a 4015 error.